At present, the products of electronic cigarette case have been widely used, not only because they are convenient to be taken along and able to accommodate electronic cigarettes, but also because their built-in reserve batteries can be used to charge the electronic cigarettes when the batteries in the electronic cigarettes have been fully drained.
However, after the electronic cigarette has been inserted into the charging interface of the electronic cigarette case to be charged, as long as the electronic cigarette has not been pulled out, the present electronic cigarette case will keep a high standby current such as from hundreds of microamps to several milliamperes, even if the electronic cigarette has been fully charged. For example, in a charging method, the electronic cigarette case will keep charging the electronic cigarette as long as the electronic cigarette has not been pulled out, so the standby current in the electronic cigarette case is still high (for example several milliamperes) even if the electronic cigarette has been fully charged. In another case, the processor in the electronic cigarette case should determine whether the electronic cigarette has been inserted through inquiring the port voltage on the charging interface discontinuously, the inquiring process will not be stopped even if the electronic cigarette has been fully charged, as a result the static current in the electronic cigarette case is high (for example hundreds of microamps). As the standby current in the electronic cigarette case is high, the electronic cigarette case will be out of power after a long time, which will bring inconvenience to users and will shorten the service life of the built-in battery of the electronic cigarette case as it may be charged frequently.